To produce an electrical plug-and-socket connection, a plug and a corresponding mating connector are needed, one of the two plug-in devices having contact elements that are insertable into socket-like openings in the mating connector. Generally, the above plug-and-socket connections are used to transmit currents or voltages.
Particularly in motor-vehicle technology, provision is made to form the so-called blade part of the plug in such a way that the contacts of the blade part are surrounded by a housing, into which the socket part of the mating connector is able to be inserted. To ensure a suitable provided polarity or allocation of the contact elements to the mating connectors, guide elements are provided both on the plug and on the mating connector which allow insertion exclusively in a defined direction. If the plug is inserted into the mating connector in a different direction, it is not possible to produce a contact.
One preferred design of these guide elements is that noses are provided on a plug part which engage in openings on sides of the mating connector. These noses are preferably arranged directly in the housing of the plug or mating connector, and are designed as a one-piece part.
Plug-and-socket connections of the aforesaid type are used in particular for transmitting currents and voltages. They are designed in such a way that they are rated either for high currents, high voltages (high-voltage range), for normal currents, normal voltages, or for low currents, low voltages (low-voltage range). High voltages lie in the range of approximately 200 V and peak currents up to approximately 50 A. Small voltages lie in the range between 5 and 12 V, and are particularly suitable for the power supply or driving of, for example, processors, RAM, EPROM, etc.
Particularly in the motor-vehicle sector, it is necessary, first of all, to transmit control currents which are provided to ensure the functions of the individual devices. Generally, they are in the high-voltage range. On the other hand, it is necessary to transmit currents, particularly in the low-voltage range, which are provided for transmitting measurement data made available by probes, for instance, in the engine compartment, to an engine-management control unit. Therefore, it is necessary to create plug-and-socket connections for various voltages or currents, so that a plurality of plug-and-socket connections are necessary.